The sterile field should be covered if it will not be immediately used or during periods of increased activity. - AORN 2019* LEARN MORE AT: tidiproducts.com/sterile-z-back-table-cover AORN Guideline for Sterile Technique. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc. 2018: electronic release.* Sterile-Z is a registered trademark of TIDI Products, LLC. ©TIDI PRODUCTS, LLC. ALL RIGHTS RESERVED.http://www.tidiproducts.com/sterile-z-back-table-cover